CCD-based bar code scanner with optical funnel

ABSTRACT

An optical funnel evenly distributes light from an array of LEDs to a bar code. A support member with a central aperture holds the LEDs. A shroud with an angled reflective interior surface spreads the light from the LEDs to the bar code. The funnel also optically isolates the LEDs from the photodector in the scanner.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to bar code scanners and moreparticularly pertains to CCD-based bar code scanners and to illuminationapparatus and to methods of illumination.

2. Description of the Related Art

Various optical readers and optical scanning systems have been developedheretofore for reading bar code symbols appearing on a label or on thesurface of an article. The bar code symbol itself is a coded pattern ofindicia comprised of a series of bars of various widths spaced apartfrom one another to bound spaces of various widths, the bars and spaceshaving different light reflecting characteristics. The readers andscanning systems electro-optically transform the graphic indicia intoelectrical signals, which are decoded into alphanumeric characters thatare intended to be descriptive of the article or some characteristicthereof. Such characters are typically represented in digital form andutilized as an input to a data processing system for applications inpoint-of-sale processing. Inventory control, and the like scanningsystems of this general type have been disclosed, for example, in U.S.Pat. Nos. 4,251,798; 4,369,361; 4,387,297, 4,409,470; 4,760,248; and4,896,026, all of which have been assigned to the same assignee as theinstant application.

As disclosed in some of the above patents, one embodiment of such ascanning system resides, inter alia, in a hand-held, portable scanninghead supported by a user, which is configured to allow the user to aimthe head, and more particularly, a light beam, at a target and a symbolto be read.

Bar code symbols are formed from bars or elements that are typicallyrectangular in shape with a variety of possible widths. The specificarrangement of elements defines the character represented according to aset of rules and definitions specified by the code or "symbology" used.The relative size of the bars and spaces is determined by the type ofcoding used, as is the actual size of the bars and spaces. The number ofcharacters per inch represented by the bar code symbol is referred to asthe density of the symbol. To encode a desired sequence of characters,element arrangements are concatenated together to form the complete barcode symbol, with each character of the message being represented by itsown corresponding group of elements. In some symbologies a unique"start" and "stop" character is used to indicate where the bar codebegins and ends. A number of different bar code symbologies exist. Thesesymbologies include UPC/EAN, Code 39, Code 128, Codabar, and Interleaved2 of 5.

A further known symbology is known as two-dimensional (2D) symbology andis discussed in detail in commonly-assigned U.S. Pat. No. 5,243,655 andU.S. Pat. No. 5,304,786, which are incorporated herein by this referencethereto. Briefly, that symbology involves a variable number of componentsymbols or "codewords" per row of a nonvolatile electro-opticalread-only memory imprinted on a substrate. Codewords in alternating rowsare selected from mutually exclusive subsets of a mark pattern, thesubsets being defined in terms of particular values of a discriminatorfunction which is illustrated in the referenced patents as being afunction of the widths of bars and spaces in a given codeword.

In the scanning systems known in the art, the light beam is directed bya lens or similar optical components along a light path toward a targetthat includes a bar code symbol on the surface. The scanning systemsfunction by repetitively scanning the light beam in a line or series oflines across the symbol. The scanning component may either sweep thebeam spot across the symbol and trace a scan line across the past thesymbol, or scan the field of view of the scanner, or do both.

Scanning systems also include a sensor or photodetector which functionsto detect light reflected from the symbol. The photodetector istherefore positioned in the scanner or in an optical path in which ithas a field of view which extends across and slightly past the symbol. Aportion of the reflected light which is reflected off the symbol isdetected and converted into an electrical signal, and electroniccircuitry or software decodes the electrical signal into a digitalrepresentation of the data represented by the symbol that has beenscanned. For example, the analog electrical signal from thephotodetector may typically be converted into a pulse width modulateddigital signal, with the widths corresponding to the physical widths ofthe bars and spaces. Such a signal is then decoded according to thespecific symbology into a binary representation of the data encoded inthe symbol, and to the alphanumeric character so represented.

The decoding process in known scanning systems usually works in thefollowing way. The decoder receives the pulse width modulated digitalsignal from the scanner, and an algorithm implemented in softwareattempts to decode the scan. If the start and stop characters and thecharacters between them in the scan were decoded successfully andcompletely, the decoding process terminates and an indicator of asuccessful read (such as a green light and/or an audible beep) isprovided to the user. Otherwise, the decoder receives the next scan,performs another decode attempt on that scan, and so on, until acompletely decoded scan is achieved or no more scans are available.

Such a signal is then decoded according to the specific symbology into abinary representation of the data encoded in the symbol, and to thealphanumeric characters so represented.

Decoding in 2D symbology is discussed particularly and shown in variousflow charts set forth in the 2D symbology patents incorporated byreference and above identified.

Another type of bar code reader is one which incorporates a detectorbased upon charge coupled device (CCD) technology. CCDs are an array ofmany detectors. The entire symbol is flooded with light from the readeror ambient light, and each CCD detector is sequentially read out todetermine the presence of a bar or a space. Such readers arelight-weight and easy to use, but require substantially direct contactor placement of the reader on the symbol to enable the symbol to beproperly read. Such physical contact of the reader with the symbol is areferred mode of operation for many applications, or as a matter ofpersonal preference by the user. However, where contact or near contactreading is not required or desired, the prior art CCD based bar codereaders lack in proper illumination mechanisms.

It is an object of the present invention to provide a CCD-based bar codescanner with improved means fo illuminating the target bar code.

SUMMARY OF THE INVENTION

In accordance with this and other objects, provided is an optical funnelfor bar code scanners with a support member having an aperturecircumferentially disposed with respect to an optical axis of thescanner, a plurality of radiant energy sources supported by the supportmember in circumferential disposition with respect to the optical axisof the scanner and a shroud member disposed in circumscribing relationto the radiant energy sources and having a central aperture incircumferential disposition with respect to the optical axis of thescanner, the shroud member having interior surface adapted for opticalmodification of radiant energy generated by the radiant energy sources.In one embodiment, the interior surface of the shroud member is adaptedto diffuse radiant energy generated by the radiant energy sources andthe assembly includes a ring-shaped member disposed circumferentially ofthe optical axis of the scanner, radially interiorly of the radiantenergy sources, and adapted to diffuse radiant energy generated by theradiant energy sources. In another embodiment, the interior surface ofthe shroud member is adapted to reflect radiant energy generated by theradiant energy sources and the assembly includes a radiant energyreflective member having an aperture circumferentially disposed withrespect to the optical axis of the scanner and in optical communicationwith the reflective interior surface of the shroud member.

In another aspect, the invention provides a support member having anaperture circumferentially disposed with respect to an optical axis ofthe scanner and a plurality of radiant energy sources supported by thesupport member in circumferential disposition with respect to theoptical axis of the scanner and having respective transmitting axes inintersecting relation to the optical axis of the scanner.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing objects and advantages of the present invention may bemore readily understood by one skilled in the art with reference beinghad to the following detailed description of preferred embodimentsthereof, taken in conjunction with the accompanying drawings whereinlike elements are designated by identical reference numerals throughoutthe several views, and in which:

FIG. 1 is a general functional block diagram of components of a scannerin accordance with the invention;

FIG. 2 shows a first embodiment of a focus portion of an optical systemin accordance with the invention;

FIG. 3 shows a second embodiment of a focus portion of an optical systemin accordance with the invention;

FIG. 4 is a front elevation of a hand-held scanner arrangement in whichthe focusing system of the invention is embodied;

FIG. 5 is a rear elevation of the FIG. 5 scanner;

FIG. 6 is a pictorial view of interior contents of the FIG. 5 scanner;

FIG. 7 is a general functional block diagram of components of thescanner of FIGS. 4-6;

FIG. 8 is a flowchart of steps practiced in a first method afforded bythe invention;

FIG. 9 is a flowchart of steps practiced in a second method afforded bythe invention; and

FIG. 10 is a flowchart of steps practiced in a third method afforded bythe invention.

FIG. 11 is a central sectional view of a first embodiment of a bar codeillumination projector for a scanner.

FIG. 12 is a central sectional view of a second embodiment of a bar codeillumination projector for a scanner.

FIG. 13 is a front elevational view of third embodiment of a bar codeillumination projector for a scanner.

FIG. 14 is a central sectional view of the third embodiment of a barcode illumination projector for a scanner.

FIG. 15 is a functional block diagram of a system for control ofillumination projection energy.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS AND PRACTICES

Referring to FIG. 1, scanner 10 includes radiant energy source 12, anoptical transmission and collection system (OTCS) discussed below,radiant energy detector 14 and bar code decoder 16. Source 12 anddetector 14 communicate with the OTCS (hereinafter, the "opticalsystem") as indicated by optical paths 18 and 20 and lines 22 furnishdetector output signals to decoder 16. The optical system has as itsobject a bar code or the like, indicated in FIG. 1 as GRAPHIC INDICIA.

Source 12 may be constituted by a light-emitting diode (LED) (shown inFIG. 2 as 12a) or other known radiant energy source. Detector 14preferably comprises a CCD array, but may be constituted by photocellsor other known radiant energy detectors. Decoder 16 may be constitutedby a microcomputer, programmed as set forth in the patents abovereferenced in the cited prior art patents, to decode the symbology ofthe bar code being addressed by the scanner.

Turning to FIG. 2, the focus portion of the optical system has first andsecond mirrors 24 and 26, which are in registry with segments of theradiant energy issuing from LED 12a. In the illustrated arrangement, LED12a provides an output beam which is circular in configuration andmirror 24 is in registry with the upper half-circle of the output beamand mirror 26 is in registry with the lower half-circle of the outputbeam. As is discussed hereinafter, the geometric configuration of theradiant energy source output beam is generally not of consequence inpracticing the invention.

Mirrors 24 and 26 are fixedly disposed in the scanner, as is the radiantenergy source 12a. Mirror 24 is disposed to reflect the LED upperhalf-circle output beam orthogonally of optical axis 28 onto mirror 30.Mirror 26 is disposed to reflect the LED lower half-circle output beamorthogonally of optical axis 28 onto mirror 32, i.e., oppositely of theenergy reflected by mirror 24, the reflective paths 34 and 36 being inalignment orthogonally of optical axis 28 as viewed from above and eachmirror having an angle of inclination (A) relative to alignment paths 34and 36.

Further reflective paths 38 and 40, respectively of mirrors 30 and 32,will be seen to contain smaller (42, 44) and larger (46, 48) images ofthe half-circles as distance progresses along optical axis 28. At onelocation along the optical axis, however, the respective upper and lowerhalf-circle images will be in planar registry, i.e., at target or objectplane 50, which is the focal plane of the focus portion of the opticalsystem. A bar code 52 resident in plane 50 will accordingly be in focusfor a scan portion of the optical system as is discussed hereinafter.

The distance D between plane 50 and the centerlines of mirrors 24 and 26is defined by the relationship:

    D=(L/2) tan                                                (2A)

where L is the distance between the vertical centerlines of mirrors 30and 32.

In use of the scanner of the invention with the optical system of FIG.2, a user energizes LED 12a and directs its output beam, in segments perthe focus portion above discussed, onto bar code 52. The user thendisplaces the scanner toward or away from the bar code until such timeas the user finds the segments of the output beam to be in positional(common plane) registry, as above discussed, to replicate the geometricconfiguration of the originally-generated radiant energy beam output ofLED 12a.

Turning to the embodiment of FIG. 3, components thereof in common withthe FIG. 2 embodiment bear the same reference numerals and letters. Anadditional component is included, namely, cylindrical lens 62. LED 12ais disposed at the focal length (F) of lens 62 and the lens converts thecircular output beam of LED 12a into a rectangular beam, which isapplied to mirrors 24 and 26 in respective upper and lowerhalf-rectangular segments. Reflective paths 38 and 40, respectively ofmirrors 30 and 32, will be seen to contain smaller (64, 66) and larger(68, 70) images of the half-rectangles as distance progresses alongoptical axis 28. At one location along the optical axis, however, therespective upper and lower half-rectangle images will be in planarregistry, i.e., at target or object plane 50, which is the focal planeof the focus portion of the optical system. A bar code 52 resident inplane 50 will accordingly be in focus for the scan portion of theoptical system.

As noted above, the geometric configuration of the output beam ofradiant energy source 12 is generally not of consequence. However,advantage attends the rectangularizing of the output beam. Thus, whenthe user moves the scanner along the optical axis to register the halfsegments, the user can also observe bar code alignment, e.g., horizonaldisposition thereof, in that the bar code is typically itself ofrectangular configuration.

FIGS. 4-6 illustrate a highly simplified embodiment of a bar code readerthat may utilize the simplified focusing system of the invention. Areader may be implemented as a hand-held scanner 72, as illustrated, ora desk-top work station or stationery scanner. In a preferredembodiment, the arrangement is implemented in a housing 74, which may beof plastic and have separable housing halves with radiant energy exitport 74a, which may be termed an optical output funnel, and radiantenergy entry port 74b, which is bounded by optical isolator 75 and maybe termed an optical input funnel. Isolator 75 is an opaque member,tapering to lens 76, and serves to restrict the lens to receipt ofprojected radiant energy as modified by reflection thereof by thescanned bar code.

Scanner 72 is generally of the style disclosed in U.S. Pat. No.4,760,248 issued to Swartz, et al., or in U.S. Pat. No. 4,896,026assigned to Symbol Technologies, Inc., and also similar to theconfiguration of a bar code reader commercially available as part numberLS 2000 from Symbol Technologies, Inc. Alternatively, or in addition,features of U.S. Pat. No. 4,387,297 issued to Swartz, et al. or U.S.Pat. No. 4,409,470 issued to Shepard, et al., both such patents assignedto Symbol Technologies, Inc., may be employed in constructing the barcode reader unit of FIG. 5. These U.S. Pat. Nos. 4,760,248, 4,896,026and 4,409,470 are incorporated herein by reference.

Referring to FIGS. 4-6 in more detail, the segmented outgoing lightbeams are generated in scanner 72 and directed to impinge upon a barcode symbol disposed on a target a few inches from the front of housing74. In a preferred embodiment, the reader unit is of a pistol-shape,i.e. having barrel and grip portions as illustrated. The focus portionof the OTCS is disposed in an uppermost cavity 92 and, as shown, theoptical axis thereof extends in parallel with the barrel portion ofhousing 74. The various mirrors and LED thereof can be seen in FIGS. 4and 6.

Lens 76 of the scan portion of the OTCS likewise has its optical axisdisposed in parallel with the barrel portion of housing 74 and LEDs 78are disposed circumferentially of lens 76. CCD array unit 80 includes anactive portion 80(a) (FIG. 4) in registry with lens 76.

An LCD panel 82 permits visual communication of decoded symbology ofscanned bar codes and other operational information as desired, forexample, display of the bar code during focusing. Indicator 84 providesindications of successful scans as by issuing output light, beeping, orthe like. Slider 86 is provided to control the level of excitation ofLEDs 78. The scanner is powered by battery 88, disposed in the gripportion of housing 74. Pushbutton 90 is a two-stage switch actuator. Inone ON position thereof, LED 12a is energized, i.e., to accomplish thefocusing phase. In the other ON position of pushbutton 90, LEDs 78 areenergized, i.e., to accomplish the scanning phase.

Printed circuit board 94 includes the various electronic circuitry ofthe scanner, particularly decoder 16 of FIG. 1, including a CPU suitablyprogrammed for decoding of the symbology of the scanned bar code and forcontrolling operation of the scanner, as explained below in connectionwith FIG. 7.

The scanner is designed to be aimed at a bar code symbol by the userfrom a position in which the reader is spaced from the symbol, i.e., nottouching the symbol or moving across the symbol. Typically, this type ofhand-held bar code reader is specified to operate in the range ofperhaps several inches.

The reader may also function as a portable computer terminal, and mayinclude a keyboard, such as described in the previously noted U.S. Pat.No. 4,409,470.

Turning to FIG. 7, focus radiant energy source 12a communicates withfocus portion of OTCS over optical path 18a and scan radiant energysource 98, comprised of LEDs 78 of FIGS. 4 and 6, communicates overoptical path 18b with scan portion 100 of OTCS.

Controller 102 energizes source 12a over line 104, energizes source 98over line 106, controls detector 14 over line 108 and controls decoder16 over line 110. In terms of control sequence, source 12a is energizeduntil focus is obtained. Then, source 98 is energized. Then, detector 14is enabled to have its CCDs read out. Lastly, decoder 16 is enabled todecode the bar code symbology in accordance with detector 14 outputsignals on line 22.

The steps of one method aspect of the invention are shown in the flowchart of FIG. 8.

In step S1, GENERATE RADIANT ENERGY BEAM WITH A GIVEN GEOMETRICCONFIGURATION, the aforementioned circular or rectangular beam isgenerated.

In step S2, SEGMENT THE GENERATED RADIANT ENERGY BEAM, the generatedbeam is partitioned by mirrors 24 and 26 of FIGS. 2 and 3.

In step S3, PROJECT SEGMENTS OF THE GENERATED RADIANT ENERGY BEAM ONTOBAR CODE, mirrors 30 and 32 so provide.

In step S4, MOVE A SCANNER HOUSING, IN WHICH THE GENERATING ANDSEGMENTING STEPS ARE PRACTICED, RELATIVE TO BAR CODE, housing 74 isadvanced toward or moved backward from the bar code.

In step S5, DISCONTINUE MOVING SCANNER HOUSING WHEN IN A POSITIONWHEREIN THE SEGMENTS FORM, ON THE BAR CODE, THE GENERATED RADIANT ENERGYBEAM IN GIVEN GEOMETRIC CONFIGURATION, the scanner housing is maintainedstationary as the beam configuration is that of FIGS. 2 or 3 on plane50.

In step S6, SCAN BAR CODE, an image of the in-focus bar code is suppliedto CCD array active area 80a.

The steps of another method aspect of the invention are shown in theflow chart of FIG. 9.

In step S7, PROVIDE A FIRST RADIANT ENERGY SOURCE, LED 12a is provided.

In step S8, DEFINE A FIRST OPTICAL PATH FOR RADIANT ENERGY GENERATED BYTHE FIRST RADIANT ENERGY SOURCE, an optical path for focusing purposesis defined, e.g., as by mirrors 24, 26, 30 and 32.

In step S9, PROVIDE A SECOND RADIANT ENERGY SOURCE, LEDs 78 areprovided.

In step S10, DEFINE A SECOND OPTICAL PATH FOR RADIANT ENERGY GENERATEDBY THE SECOND RADIANT ENERGY SOURCE, exit port 74b is provided in thescanner housing, as is lens 76 with isolation member 75.

In step S11, ENERGIZE THE FIRST RADIANT ENERGY SOURCE, and step S12,OBTAIN A FOCUS CONDITION FOR BAR CODE USING RADIANT ENERGY IN THE FIRSTOPTICAL PATH, the focus condition of FIGS. 2 or 3 is obtained by usingthe optical path defined as by mirrors 24, 26, 28 and 30.

In step S13, SCAN BAR CODE USING RADIANT ENERGY IN THE SECOND OPTICALPATH WHILE IN FOCUS CONDITION, the bar code image, as illuminated by theoutput of LEDs 78 is conveyed to the CCD.

The flow chart of FIG. 10 will be seen to include steps S14 through S19,which correspond respectively to steps S7, S8 and S10 through S13, step9 being omitted. This practice relies on ambient, environmentalradiation incident on the bar code.

The radiant energy projection and collection arrangement of FIGS. 6 and7 arranged the LED array and lens 76 in communication with a bar codethrough isolated optical funnels without intervening diffusion orreflection of the output beam. Preferred arrangements are now discussedin connection with FIGS. 11-14, in which showings of isolation structureare omitted, for simplicity, but may be included, as per isolationmember 75 of FIGS. 6 and 7.

Referring to FIG. 11, an illumination projector or scanner opticalfunnel assembly 112 includes PCB 114 having central aperture 114a, withwhich lens 76 is placed in registry. LEDs 116 and 118 and others (notshown) are supported on PCB 114. Conical shroud member 120 is supportedalso by PCB 114 and includes central aperture 120b in registry withaperture 114a.

Interior surface 120a of conical shroud member 120 is treated to diffusethe LEDs'output light, for example, by zinc-white painting thereof.Diffuser ring 122 is secured between PCB 114 and conical member 120 andis disposed coaxially of optical axis 124, preferably being comprised ofDelrin. High uniform illumination is achieved for the bar code uponenergization of the LEDs.

Scanner optical funnel assembly 112 may be used with either a shortfocal length lens or an optical pinhole. The pinhole be an adjustableaperture formed as a liquid crystal plate.

Referring to FIG. 12, scanner optical funnel assembly 126 includes PCB128 having central aperture 128a, with which lens 76 is placed inregistry. LEDs 130 and 132 and others (not shown) are supported on PCB128 peripherally of optical axis 134. Shroud member 136 is supportedalso by PCB 128 and includes central aperture 136b in registry withaperture 128a. Interior surface 136a of shroud member 136 is treated tobe positively reflective of incident light energy to reflect the sameonto arcuate positively reflective mirror 138, the central portion isapertured as indicated at 138a. Bar code illuminating light isaccordingly generated and applied to a bar code upon energization ofLEDs 130, 132 and the unshown LEDs mounted therewith on PCB 128. Funnelassembly 126 is particularly suitable for long range bar code reading.

Turning to FIGS. 13 and 14, scanner optical funnel assembly 140 includesPCB 142 having central aperture 142a, with which lens 76 is placed inregistry. LEDs 144 and 146 and others (FIG. 13) are supported on PCB142, being surface-mounted at angle B and projecting light alongrespective transmission axes which intersect optical axis 148. Angle Bdefines a plane at which the projected light is focused at a distance C,the arc tangent of B being C/D, where D is the distance between an LEDand optical axis 148.

Slider 86 (FIG. 5) is positioned as desired to control the energizationlevels of the LEDs of the optical funnel assemblies of FIGS. 11-14. Inthis connection, 2-D symbols printed or etched on different substrateshave different reflection and are accordingly best scannable atdifferent scanning energy levels.

The optical funnel assemblies of FIGS. 11-14 are particularly effectivefor reading miniature two-dimensional symbols, e.g., laser etched markson IC chips. They nonetheless have reading regular size bar codes andnano-symbol compatibility.

Turning to FIG. 15, slider 86 has a central (OFF) position and ON leftand right positions, corresponding respectively with the UP and DOWNinputs to pulse counter 150. Depending on the user selection of the leftand right positions for slider 86, the count state of counter 150 willbe increased or decreased, based on input to the counter of the outputof square wave generator 152. The output of the counter 150 is convertedto analog form by D/A converter 154 and applied LED driver 156, whichmay be configured as an emitter-follower transistor stage, where theLEDs are connected to the transistor emitter and accordingly energizedat a desired level. In this connection, the LEDs are responsive tovoltage levels applied thereto to output light corresponding inintensities to the applied voltage levels.

Although the present invention has been described as aforesaid, it isnot limited to such embodiments, but may also be applicable to morecomplex indicia scanning applications. It is conceivable that thepresent invention may also find application for use with various machinevision or optical character recognition applications in whichinformation is derived from other types of indicia such as characters orfrom the surface characteristics of the article being scanned.

By way of summary and introduction to the ensuing claims, the inventionwill be seen to provide a support member having an aperturecircumferentially disposed with respect to an optical axis of thescanner, a plurality of radiant energy sources supported by the supportmember in circumferential disposition with respect to the optical axisof the scanner and a shroud member disposed in circumscribing relationto the radiant energy sources and having a central aperture incircumferential disposition with respect to the optical axis of thescanner, the shroud member having interior surface adapted for opticalmodification of radiant energy generated by the radiant energy sources.In one embodiment, the interior surface of the shroud member is adaptedto diffuse radiant energy generated by the radiant energy sources andthe assembly includes a ring-shaped member disposed circumferentially ofthe optical axis of the scanner, radially interiorly of the radiantenergy sources, and adapted to diffuse radiant energy generated by theradiant energy sources. In another embodiment, the interior surface ofthe shroud member is adapted to reflect radiant energy generated by theradiant energy sources and the assembly includes a radiant energyreflective member having an aperture circumferentially disposed withrespect to the optical axis of the scanner and in optical communicationwith the reflective interior surface of the shroud member.

In another optical funnel assembly aspect, the invention provides asupport member having an aperture circumferentially disposed withrespect to an optical axis of the scanner and a plurality of radiantenergy sources supported by the support member in circumferentialdisposition with respect to the optical axis of the scanner and havingrespective transmitting axes in intersecting relation to the opticalaxis of the scanner.

While several embodiments and variations of the present invention for anautomatic focusing system and scanner are described in detail herein, itshould be apparent that the disclosure and teachings of the presentinvention will suggest many alternative designs to those skilled in theart.

What is claimed is:
 1. An optical funnel assembly for a bar codescanner, comprising:a) a support member having an aperturecircumferentially disposed with respect to an optical axis of saidscanner; b) a plurality of radiant energy sources supported by saidsupport member in circumferential disposition with respect to saidoptical axis of said scanner; c) a shroud member disposed incircumscribing relation to said radiant energy sources and having acentral aperture in circumferential disposition with respect to saidoptical axis of said scanner, said shroud member having an interiorsurface in a non-perpendicular relationship with optical axis and theradiant energy sources, said shroud member adapted for opticalmodification of a substantial portion of said radiant energy generatedby said radiant energy sources; and an optical isolator disposedinteriorly and circumferentially of said plurality of radiant energysources for preventing the generating radiant energy from impinging upona photodetector prior to exiting said shroud member.
 2. The opticalfunnel assembly claimed in claim 1, wherein said interior surface ofsaid shroud member is adapted to diffuse radiant energy generated bysaid radiant energy sources.
 3. The optical funnel assembly claimed inclaim 2, further comprising a ring-shaped member disposedcircumferentially of said optical axis of said scanner, radiallyinteriorly of said radiant energy sources and radially exteriorly fromsaid optical isolator, and adapted to diffuse radiant energy generatedby said radiant energy sources.
 4. The optical funnel assembly claimedin claim 1, wherein said radiant energy sources are LEDs.
 5. The opticalfunnel assembly claimed in claim 1, wherein said interior surface ofsaid shroud member is adapted to reflect radiant energy generated bysaid radiant energy sources.
 6. The optical funnel assembly claimed inclaim 5, a radiant energy reflective member having an aperturecircumferentially disposed with respect to said optical axis of saidscanner and in optical communication with the reflective interiorsurface of said shroud member.
 7. The optical funnel assembly claimed inclaim 6, wherein said radiant energy reflective member is of arcuateconfiguration transversely of said optical axis of said scanner.
 8. Theoptical funnel assembly claimed in claim 5, wherein said radiant energysources are LEDs.
 9. The optical funnel assembly claimed in claim 1,wherein said support member is a PCB.
 10. The optical funnel assemblyclaimed in claim 5, wherein said support member is a PCB.